Buttonhole-sewing machine



J. FOSSA BUTTONHOLE SEWING MACHINE Filed April 9 1920 2 Sheets-Sheet 1 1,487,325 J. FQSSA.

BUTTONHOLE SEWING MACHICNE March 18, 1924.

2 Sheets-Sheet 2 Filed April 9 1920 tached to the work, and extends from hut- @etented Mar. 18, $24.

uwrrso srsrns se ne FATENT JOSEPH 3033A, GE 'DANVERS, MASSACHUEETTS, ASIGNOR TO 'o'znrrm SHOE MACHHL ERY CGEZ'GRATION, 0F PATEBSQN, NEW JERSEY, A CORPORATION GE NEW 17 EESEY.

BUTTONHOLlE-SEWING resomnn Application end s in 9, mo. sermon. 372,452.

To all whom it may concern Be it known that I, Josnrn FOSBA, e citizen of the United States, residing et Danvers, in the county of Essex and State of Massec-husetts, have invented certain new and useful Improvements in Buttonhole- Sewing Machines; and I do hereby declare the following to he a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it ap-pertains to make and use the same.

The invention relates to buttonhole sewing machines in which overseam stitches are formed about the edge of the buttonhole by the cooperation of upper and under thread mechanisms, and more particularly to means for controlling the under thread.

lln sewing a series of lhuttonholes in e, piece of work upon the type of machines to which the present invention more particularly relates the under thread remuins ettonhole to buttonhole along the under shrfaee of the Work. In spacingthe work the operator, therefore, frequently draws a sur plus amount of under-thread through the under-thread tension so that the underthread is slack at the beginning of the succeeding buttonhole, with a resulting undesirable looseness in the initial stitch or stitches of the seam. The spacing of the work also involves drawing the under-thread through the under-thread tension and in doing oertein classes of work, which require a comparatively heavy tension on the under-.

thread, ithas been roposed to release the tension at the comp etion of the sewing to avoid danger of breaking the thread and the strain on the operetor'incident to drawing the thread through the tension. This, however, is likely to increase the sur lus thread between the completed button ole end the under-thread tension, and to objeotionably increase the number of loose stitches formed at the beginning of the next huttonhole, since comparatively little of the under-thread enters into each stitch in doing "that class of work which requires e heavy under-thread tension.

The resent invention avoids or eliminates the obyections outlined above by the rovision 01: means for taking up any slack t read between the under-thread tension and the reviously sewed buttonhole after the work as been spaced and prior to the sewing of therein.

the initial stitch of the huttonhole seam, and by the provision of means for drswing through the under-thread tension suficient thread to permit the spacing of the work without releasing the tension for the underthread. These functions are preferably effected by the some means which, in its preferred form, com rises a thread take-u and pull-ofi' arrange between the under-t read tension and the under needle, and operated at the beginning of a buttonhole mahng c ole to take up it loop of thread between t 1e tension and needle, and operated at the end of the huttonhole making cycle to give 4 up this loop of thread to provide slack thread take-up and pull-0d, in taking up lts loop at the be inning of the next buttonhole makmg cyc e, takes up any slack thread between the previously sewed buttonhole and the un den-thread tension, and thereafter draws thread through the under-thread tension to he held until again given up at the end of this outtonhole making cycle.

The invention will be readily understood from an inspection of the accompanying drawings and the following detailed desoription of the mechanism' illustrated in the drawings Fig. l is n vertical sectional view showing so much of e buttonhole sewing machine as is necessary to illustrate the application of the present'invention thereto. Fig. 2 is a 11m view on e larger scale, showing the un er-thread mechenism and a part of the clamp carrier. Fig. 3 is a, view similer to Fig. 2, showing the 'partsin n dilierent position, and Fig. 4 is a vertical sectional view on line 4-4, Fig. 2.

the eye and bar ends of e huttonho e. The

work is held by clamps 14 mounted on supporting plates 16, which are in turn mounted on a clamp carriage 18. The clamp carria e is moved lengthwise of the buttonhole to ring the work from cutting to sewing osition and the clamp carriage is moved aterally'and the stitch-forming mechanism is rotated by mechanisms fully described in said patents.

The under-thread tension is mounted on the turret and comprises two tension disks 20, pressed together by spring 22, the pressure of which may be adjusted to secure the tension requisite for the class of work to be done. The under-thread passes from the hollow link 24, which forms a part of the mechanism for actuating the under needle and looper, between the tension disks,

to an eye 26 in the end of a lever 28 and thence to an eye 30 on the needle carrier 32, from which it leads through the eyes of the under needle. The lever is mounted in the turret and its hub surrounds and forms the bearing ,for the rock shaft 34 on which the looper arm 36 is carried. During the sewing the lever is held in position against the stop 38 by a torsional spring 40, as indicated in Fig. 3, and the eye 26 in the lever corresponds to the usual fixed thread guide from which the under-thread leads to the eye on the needle carrier. 'When the sewing mechanism stops the under needle is brought torest in its retracted position and the eye 26 holds a loop of thread between the tension and the needle carrier. The lever 28 is actuated to give up this loop and thus provide slack thread for the s acing of the work by the movement of t e work clamp carriage from sewing to cutting position at the completion of the buttonhole making cycle. As shown the meansfor thus actuating the lever comprises a lever 42 mounted on the turret bracket, and arranged to enga e an arm 44 projecting from the hub of t e lever 28 when the turret is in stopped position. A bar 46 secured to the clamp carriage is arranged to engage and actuate the lever 42. When the sewing mechanism is stopped at the completion of the sewing of the buttonhole the turret is in the position indicated in F ig.v

2 and the lever42 and the bar 46 are in the position indicated in Fig. 3. As the clamp carriage moves from sewing to cutting position the bar 46 engages the lever 42 andswings it into the position indicated in Fig. 2 so that the lever acts on the arm 44 of the lever 28 to move the thread eye 26 from the position of Fig. 3 to the position of Fig. 2 and thereby give up its loop so that sufiicient slack thread is provided between the tension and the work to permit free movement of the work into position for the sewing of the succeeding buttonhole. At the beginning of the next button to take up any slack thread which may remain between the work and the tension disks 20 and after any slack thread has been taken it acts as a pull-off to pull thread through the tension. It thus draws a loop of thread between the undenr needle and under-thread tension to be given up at the end of this buttonhole making cycle in'supplying slack thread for the spacing of the work.

While it is preferred to employ the spe cific' construction and arrangement of parts shown and described in embodying the invention in a machine of the patent above referred to, it will be understood that this construction and arrangement is not essential to the broader features of the invention, and may be varied or modified as found desirable or best suited to the construction and arrangement of the cooperating parts in the machine in which it is to be embodied.

What is claimed is:

l. Aibuttenhole sewing machine having, in combination, upper and under thread mechanism, including an under-thread tension located under the work and means for in combination, upper and under thread mechanism, including an under-thread tension, and means for taking up slack thread between the tension and a previously stitched. buttonhole before startin the sewing at the beginning of a button ole mak ing cycle.

3. A buttonhole sewing machine having. in combination, upper and under thread mechanism, including an under-thread tension, means for pulling thread through the tension prior to the beginning of the sowing, and for giving up slack thread between the work and the tension at the completion of the sewing.

4. A buttonhole sewing machine having, in combination, upper..,and under thread mechanism, including an under-thread tension, a pull-off, and means for actuating the pull-off to pull thread through the tension prior to the beginning of the sewing and to give it up after the sewing is completed.

5. A buttonhole sewing machine having, in combination, upper and under thread mechanism, including an under needle and an under-thread tension, means for pulling thread through the tension to form a loop ning of a buttonhole making cycle, and for giving up the loop at the end of the cycle to be drawn forward in spacing the work.

6. A buttonhole sewing machine having, in combination, upper and under thread mechanism, includ ng an under-thread tension, a clamp carriage movable before and after the sewing, and a pull-ofi' for the under-thread o erated by .said movement of the clamp carria e.

7 7. A buttonho e sewing machine having, in combination, upper and under thread mechanism, including a needle for the under thread, a turret carrying the under-thread mechanism, an under-thread tension on the turret, a pull-off between the tension and needle, and means for actuating the pull-0d to pull thread through the tension and to give it up at the end of the buttonhole making cycle to be drawn through the needle 'u spacing the work.

8. A buttonhole sewing machine having, in combination, upper and under thread mechanism, includlng a needle for the untier-thread, a turret carrying the underthread mechanism, an under-thread tension on the turret, a pull-0E between the tension and needle, means for actuating the pull-off to pull thread through the tension prior to the sewing, and for actuating it at the end of the buttonhole making cycle to give up said thread to be drawn through the needle in spacing the work.

9. A sewing machine having, in combination, upper and under thread mechanism, a turret carrying the under thread mechanism, an under thread tension on the turret, and means for pulling thread through the tension and for giving it 11 at the completion of the sewing to be rawn forward in spacing the work.

JOSEPH FOSSA. 

